[  643.246655] usb 2-1: USB disconnect, address 2
[  663.093109] usb 2-1: new full speed USB device using ohci_hcd and address 3
[  663.409791] usb 2-1: configuration #1 chosen from 1 choice
[  663.422026] usb 2-1: New USB device found, idVendor=2001, idProduct=3c00
[  663.422058] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[  663.422067] usb 2-1: Product: 802.11g WLAN Adapter    
[  663.422074] usb 2-1: Manufacturer: ANI 
[  664.631468] phy0: Selected rate control algorithm 'pid'
[  665.065967] Registered led device: rt2500usb-phy0:radio
[  665.068869] usbcore: registered new interface driver rt2500usb
[  692.429861] ADDRCONF(NETDEV_UP): wlan0: link is not ready
[  694.125465] wlan0: authenticate with AP 00:13:46:51:10:65
[  694.127508] wlan0: authenticated
[  694.127536] wlan0: associate with AP 00:13:46:51:10:65
[  694.130502] wlan0: RX AssocResp from 00:13:46:51:10:65 (capab=0x431 status=0 aid=1)
[  694.130522] wlan0: associated
[  694.138610] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[  704.793080] wlan0: no IPv6 routers present
[ 1093.359818] RPC: Registered udp transport module.
[ 1093.359844] RPC: Registered tcp transport module.
[ 2418.297105] ondemand governor failed, too long transition latency of HW, fallback to performance governor
[ 4675.685561] wlan0: disassociated
[ 4676.686006] wlan0: associate with AP 00:13:46:51:10:65
[ 4676.688605] wlan0: RX ReassocResp from 00:13:46:51:10:65 (capab=0x431 status=17 aid=1)
[ 4676.688627] wlan0: AP denied association (code=17)
[ 4676.885138] wlan0: associate with AP 00:13:46:51:10:65
[ 4676.887520] wlan0: RX AssocResp from 00:13:46:51:10:65 (capab=0x431 status=17 aid=1073)
[ 4676.887539] wlan0: AP denied association (code=17)
[ 4677.085099] wlan0: associate with AP 00:13:46:51:10:65
[ 4677.087534] wlan0: RX AssocResp from 00:13:46:51:10:65 (capab=0x431 status=17 aid=1073)
[ 4677.087552] wlan0: AP denied association (code=17)
[ 4677.289225] wlan0: association with AP 00:13:46:51:10:65 timed out

Now, I don't have access to the network. I, now, issue "iwconfig wlan0 ap any"
and it goes working again:

[ 5841.260475] wlan0: authenticate with AP 00:13:46:51:10:65
[ 5841.262529] wlan0: authenticated
[ 5841.262560] wlan0: associate with AP 00:13:46:51:10:65
[ 5841.265499] wlan0: RX AssocResp from 00:13:46:51:10:65 (capab=0x431 status=0 aid=1)
[ 5841.265519] wlan0: associated